Standard UK mattress sizes
Before we even begin helping you decide what size mattress you need, let's start off with a quick overview of what mattress sizes are available.
Different countries have different mattress sizes. 😳
Here is an overview of the standard UK mattress sizes:
|Metric dimensions W x L (cm)||Imperial dimensions W x L (feet)|
|Cot||60 x 120||1'9" x 3'9"|
|Toddler||70 x 140||2'3" x 4'6"|
|Small single||75 x 190||2'6" x 6'3"|
|Single||90 x 190||3'0" x 6'3"|
|Small double||120 x 190||4'0" x 6'3"|
|Double||135 x 190||4'6" x 6'3"|
|King||150 x 200||5'0" x 6'6"|
|Super king||180 x 200||6'0" x 6'6"|
|Emperor||200 x 200||6'6" x 6'6"|
Most UK retailers will only stock UK mattress sizes, though some brands will also have European mattress size options available.
Simba Sleep, for example, sells its acclaimed Simba Hybrid mattress in a variety of UK sizes but also offers European single, European double, and European queen size options.
IKEA mattresses are also more readily available in Euro sizes.
Let's take a closer look at the different UK mattress sizes.
UK cot mattresses
The standard UK cot mattress has dimensions of 60 x 120 cm (1'9" x 3'9").
|Dimensions (W x L):||60 x 120 cm (1'9" x 3'9")|
|Best suited to:||Cot bed frames, babies under the age of 2|
These mattresses have been exclusively designed to fit cot beds and are meant for use by babies under the age of 2. 👶
We're big fans of more natural cot mattresses, like the Little Green Sheep Natural Twist mattress.
We don't cover cot mattresses at length in this article but feel free to head over to our guide on cot mattresses and beds for more information.
UK toddler mattresses
The standard UK toddler mattress has dimensions of 70 x 140 cm (2'3" x 4'6").
|Dimensions (W x L):||70 x 140 cm (2'3" x 4'6")|
|Best suited to:||Toddlers and small children aged 2 - 6|
Toddler mattresses are one size up from cot mattresses. 🧒
They are intended to be used by toddlers and small children between the ages of 2 and 6.
Some mattresses, like the Mamas & Papas Premium Pocket Spring mattress, have dual sides for use by both babies and toddlers.
After age 6, most children are able to move on to adult small single or single-sized mattresses. 🙌
UK small single mattresses
The standard UK small single mattress has dimensions of 75 x 190 cm (2'6" x 6'3").
|Small single mattress|
|Dimensions (W x L):||75 x 190 cm (2'6" x 6'3")|
|Best suited to:||Children, narrow bed frames, guest beds|
Small single beds have been designed to fit narrower kids' bed frames. 🛏
They're also a great save-spacing option for spare rooms, though this isn't the most comfortable size for adults.
UK single mattresses
The standard UK single mattress has dimensions of 90 x 190 cm (3’ x 6’3”).
|Dimensions (W x L):||90 x 190 cm (3’ x 6’3”)|
|Best suited to:||Children, teenagers, young adults, small bedrooms|
This is a common size in children's bedrooms, but it also works well for teenagers, students, or in very small bedrooms. 👩🎓
We wouldn't recommend a single bed as a long-term comfort choice for adults.
That said, many couples choose to combine two single mattresses to form one large bed. 👩❤️👨
This ensures that both partners have enough space to move comfortably and also allows for different firmness requirements to be met.
We'd highly recommend doing this for partners with a weight difference of 15 kg (33 lbs) or more.
UK small double mattresses
The standard UK small double mattress has dimensions of 120 x 190 cm (4' x 6'3").
|Small double mattress|
|Dimensions (W x L):||120 x 190 cm (4' x 6'3")|
|Best suited to:||Teenagers, students, young adults with limited bedroom size|
A small double mattress is a good option that falls between standard single and standard double mattresses.
These beds are a popular choice for teenagers, students, or young adults who often have budget and space constraints. 💸
Some of the best budget mattresses, like the Simba Essential, are available in small double options.
Small double beds are also convenient for guest bedrooms.
UK double mattresses
The standard UK double mattress has dimensions of 135 x 190 cm (4’6" x 6’3”).
|Dimensions (W x L):||135 x 190 cm (4’6" x 6’3”)|
|Best suited to:||Women, single adults, couples with limited bedroom space|
This is the most popular mattress for adults in the UK and will fit an average-sized bedroom.
It's a great option for singles wanting a bit more sleeping space and couples with smaller bedrooms.
The Emma Original is a fantastic double mattress for a great night's sleep.
That said, we wouldn't recommend a double mattress to couples in the long term.
We'll elaborate on this in more detail further down. 👇
Since mattresses should be at least 10 cm longer than the tallest person using the bed, we also wouldn't recommend double mattresses to anyone taller than 180 cm (6'0").
UK king mattresses
The standard UK king mattress has dimensions of 150 x 200 cm (5’ x 6’6”).
|Dimensions (W x L):||150 x 200 cm (5’ x 6’6”)|
|Best suited to:||People taller than 180 cm, single adults, couples|
The king-size mattress is our preferred choice for couples. 👑
It offers enough space for two people to sleep comfortably.
But, it's also longer than average and better suited to people taller than 180 cm (6'0").
A mattress like the Nectar mattress, with good support and excellent motion isolation, is a fantastic king-size mattress choice for couples.
Single adults who like a lot of space or those sharing their bed with a young child or pet will also really enjoy the size of a king bed. 🐈
UK super king mattresses
The standard UK super-king-size mattress has dimensions of 180 x 200 cm (6’ x 6’6”).
|Dimensions (W x L):||180 x 200 cm (6’ x 6’6”)|
|Best suited to:||Couples, families, people of larger builds or heavier weights|
The super king mattress is the premium choice for couples.
It ensures that both partners have more than enough space to sleep comfortably without worrying that they'll disturb each other.
Super-king mattresses are also a good choice for people (and couples) of larger builds or heavier weights. ⚖️
The Simba Hybrid is one of our top choices, offering premium comfort and support.
Unfortunately, super-king mattresses won't fit everyone's budget or bedroom size.
UK emperor mattresses
The standard UK emperor mattress measures 200 x 200 cm (6’6” x 6’6”).
|Dimensions (W x L):||200 x 200 cm (6’6” x 6’6”)|
|Best suited to:||Luxury rooms, families, hotel suites|
The emperor bed is the largest mattress size available in the UK.
It is a luxurious choice that offers more than enough space and can be used quite comfortably by three people or more (parents, children, and pets). 🙍♂️🙍♀️🧒🐶
Emperor beds may be the largest standard size but they are not commonly available as bed-in-a-box mattresses.
The only bed-in-a-box brand that we know of that sells emperor beds is Otty.
You'll be more likely to find emperor-sized mattresses at traditional retailers. 🛒
How wide should your mattress be?
If you're sleeping by yourself, the width of your mattress doesn't really matter too much. 🤔
You'd be able to sleep comfortably on most adult mattresses.
Of course, if you're a very restless sleeper and frequently toss and turn at night, a slightly wider mattress will be more comfortable. 🕺
Width becomes more of an issue, though, if you share your bed with a partner.
The double bed size, available from some of our favourite brands, like Nectar, is the most popular choice for adults in the UK.
But, this mattress is only 135 cm (4’6") wide - giving each partner only 67.5 cm (2'3") of space.
That's narrower than a toddler mattress! 😳
Sure, if you're a snuggle bunny and you and your partner love being cosy with little room to move, this isn't a train smash.
But, it also means that you're more likely to disturb your partner every time you change sleep position, eventually resulting in poor sleep. ☹️
This becomes even more of an issue if you take build and body size into account.
Here's a simple test to determine if a mattress is large enough for two people:
- Lie next to your partner on the mattress.
- Both of you should lie on your backs and put your hands behind your head, with elbows sticking out.
- If your elbows don't touch, the mattress is big enough and you'll have enough room to sleep comfortably.
- If your elbows touch, you'll need a bigger mattress.
If you and your partner are both on the smaller side, you wouldn't have much of a problem.
But if you're of average or above-average build, height, or weight, a double mattress will quickly become too small.
This is why we'd always recommend couples opt for a king-size bed or larger. 👑
One of our favourite mattresses for couples is the DreamCloud Luxury Hybrid.
It's large, luxurious, and oh-so-comfortable.
You can also read our full guide on the best mattresses for couples in the UK.
How high should your mattress be?
The height or thickness of a mattress does not affect the overall mattress size.
To measure a mattress's size, we only look at the width and length of the mattress.
But, the thickness or height of a mattress affects the overall look and feel of your bed.
As a rule of thumb:
The thicker the mattress, the more comfortable and luxurious it will be.
Thicker mattresses also tend to last longer.
Here's a quick guide:
- For foam mattresses, we recommend a minimum mattress thickness of 18 cm (7 inches).
- For spring mattresses, we recommend a minimum mattress thickness of 23 cm (9 inches).
Most standard bed-in-a-box mattresses, like the Emma Original, have a height of 25 cm (10 inches).
This is a comfortable thickness that will look nice on any bed frame. 🙃
Conveniently, this standard size is also practical as it ensures most bedding will fit!
But, there are a few thinner, lighter options available, like the Eve Lighter mattress.
This mattress only measures 20 cm (7.8 inches).
Thinner mattresses are more budget-friendly and are a great option for children or guest bedrooms.
Similarly, there are also a few thicker options available, like the DreamCloud Luxury Hybrid.
This mattress has an average height of 28 cm (11 inches).
Thicker mattresses tend to give bedrooms a more luxurious feel. 🌟
They can also be more convenient for the elderly, as it makes getting in and out of bed easier.
What's the best mattress size?
As you've seen, there's no one best mattress size.
The right mattress size for you will depend on your budget, sleeping requirements, relationship status, and the size of your bedroom.
While you can opt for a few custom sizes, we'd highly recommend sticking to standard UK mattress sizes.
This makes finding suitable bedding a breeze.
Need some mattress recommendations?
Here are a few of our favourite UK mattresses: